The invention relates to networked devices. More particularly, the invention relates to providing multicast capability with both Internet Group Management Protocol (IGMP) and Group Multicast Registration Protocol (GMRP).
Multicasting of network traffic is communication between a single sender and multiple receivers on the network. Typical uses include the updating of mobile personnel from a home office and the periodic issuance of online newsletters. Internet Group Management Protocol (IGMP) can be used for multicasting. One embodiment of IGMP is described in the Internet Engineering Task Force (IETF) Request for Comments (RFC) 1112, published in August 1989.
IGMP is a layer 3 (network layer) protocol, which means that IGMP methods are used to control multicast traffic with network routers. Routers direct multicast traffic to switches having nodes that are intended to receive the multicast traffic. However, as multicast traffic increases additional pruning is desirable at the switch level (layer 2) in order to more efficiently use available switch bandwidth. IGMP has been applied to switches to provide additional pruning, but because IGMP is a layer 3 protocol, such IGMP-based layer 2 pruning is inefficient.
The Institute of Electronics and Electrical Engineers (IEEE) standard 801.2D/D15, published Nov. 24, 1997 describes the Generic Attribute Registration Protocol (GARP), which is a layer 2 protocol. The GARP Multicast Registration Protocol (GMRP) can be used for multicast pruning at the switch (layer 2) level. GMRP provides improved pruning performance compared to IGMP. However, switching multicast pruning from a layer 3 protocol to a layer 2 protocol is expensive because both switches and routers must be upgraded.
A first set of multicast registrations is processed according to a first network protocol. A second set of multicast registrations is processed according to a second network protocol. The first set of multicast registrations are received and processed as a predetermined type of multicast registrations according to the second network protocol.